Conference Papers

A two-demensional, depth-averaged, finite-difference, flow/transport model, SIM2D, is being used to simulate tidal circulation and transport in the Port Royal Sound, South Carolina, estuarine system. Models of a subregion of the Port Royal Sound system have been derived from an earlier-developed model of the entire system having a grid size of 600 ft. The submodels were implemented with...

The transport of sediment through a hydrologic system or basin is an extremely complex phenomenon. Many factors affect this movement. Criteria are established for an 'ultimate' or complete sediment data set, and guidelines are given for the collection of alluvial data. The paper describes what parameters need to be measured and stored to obtain a complete sediment and hydraulic data set...

An investigation is being conducted to collect and interpret continuous records relating to the flow characteristics of the Pamlico River Estuary, North Carolina, and to calibrate and validate a numerical model of estuarine hydrodynamics. The study reach is 50 kilometers long and ranges in width from 330 meters at the upstream boundary to 6.4 kilometers at the downstream end. Water...

An 18-month study of six Louisiana beaches determined the extent, composition, and possible sources of beach litter. Data showed that from 2590 to 23,154 items may be encountered along any one-mile stretch of Louisiana beach, depending upon location and season, and that densities of litter ranged from 5 to 28 items per 100 m2. Plastics constituted 47% of the total, followed by...

The Paleocene coal-bearing sequences in the northern Powder River Basin are contained in the Tongue River Member of the Fort Union Formation and include anomalously thick (54 m) subbituminous coals. These thick coals have been the target of exploration and development for the past few decades. For the past decade, these coals have also been the object of depositional modeling studies...

This paper examines forecasts of changes in watershed runoff in the Delaware River basin that result from a range of predicted effects of increased atmospheric carbon dioxide (CO2) on future precipitation, temperature, and stomatal resistance of plants. A deterministic hydrologic model, TOPMODEL, was driven with stochastic inputs of temperature and precipitation to derive the forecasts...

Contrary to the findings of previous studies of channel-controlled stream reaches, it was found that, in four reaches of a small stream characterized by a series of pools and riffles, reaeration coefficients decrease with decreasing discharge. In the reach with the most pool-and-riffle development, the measured reaeration coefficient under low-flow conditions was 86 percent less than its...

The objective of this study is to investigate changes in the spatial distribution of salt in the Delaware Estuary resulting from climate induced changes in freshwater inflows and in the position of mean sea level. The approach adopted for this study is composed of two parts: An analysis of existing physical data in order to derive a basic understanding of the salt dynamics, and numerical

Four examples show the effect of vegetation on stage, discharge or frequency of floods. An 8-year growth of trees on the streambed at site 1 increased channel roughness enough to cause the average water surface elevations that were computed for 10-year and 100-year floods to be 0.49 and 0.91 meters higher than those for a channel without vegetation. A 6-year growth of vegetation and...

Methods in use by the U.S. Geological Survey to estimate flood-frequency characteristics for urban watersheds are compared with estimates based on the Soil Conservation Service TR-55 model. Data from four small urban watersheds in Georgia are used in the flood-peak and hydrograph comparisons.

Computer processing and high resolution graphics display of geochemical data were used to quickly, accurately, and efficiently obtain important decision-making information for tin (cassiterite) exploration, Seward Peninsula, Alaska (USA). Primary geochemical dispersion patterns were determined for tin-bearing intrusive granite phases of Late Cretaceous age with exploration bedrock

Digital elevation models (DEMs) are being used to determine variable inputs for hydrologic models in the Delaware River basin. Recently developed software for analysis of DEMs has been applied to watershed and streamline delineation. The results compare favorably with similar delineations taken from topographic maps. Additionally, output from this software has been used to extract other...